1. Field of the Invention
The present invention relates generally to a soymilk and tofu, or bean curd, manufacturing method and, more particularly, to a method for manufacturing such soymilk and tofu as have no grassy smell and are excellent in taste and flavor, especially in the generally accepted rich and milky taste.
2. Description of the Prior Art
In the prior art method for manufacturing soymilk and tofu, soybeans as raw material, after they have been dipped in water, are usually ground while they are being added with water, so that soybean slurry may be obtained. Then, the soybean slurry is heated and soy pulp, or “okara”, is separated therefrom, so that soymilk of a temperature of 70 to 90° C. may be obtained. Then, an appropriate quantity of coagulant is added thereinto and agitation is done for coagulation and tofu is obtained.
Also, in order to obtain a tasty and high quality soymilk by ultra-finely breaking soymilk particles into particle sizes of 0.2 to 0.5 μm, it is disclosed that soymilk, after the soy pulp has been separated therefrom, is applied with a heating treatment under a pressure of 0.2 to 0.3 MPa and a temperature of 105 to 110° C. and then applied with a homogenizing treatment by a homogenizer under a pressure of 20 to 50 MPa and a temperature of 85 to 90° C. (the Japanese laid-open patent application Sho 63-63358).
However, in this prior art method for manufacturing the soymilk, the heating temperature is low and removal of the grassy smell is not sufficient. Also, the heating treatment, that is done before the homogenizing treatment, is assumed to be carried out by a batch type treatment in which, for example, an autoclave is used and this does not suit a production in a large quantity.
Also, a soymilk manufacturing method is disclosed in which an ultra-high pressure is used such that a pressure of 300 to 500 MPa is applied to the soymilk for ten minutes after the soy pulp has been separated but before the heating treatment is done (the Japanese laid-open patent application Hei 5-244866). But, even in the soymilk obtained by this method, the grassy smell is not sufficiently removed and moreover the milky taste also is not sufficiently attained.
Thus, it is an object of the present invention to provide a soymilk and tofu manufacturing method in which a ratio of finely broken soymilk particles is increased and thereby such soymilk and tofu as have no grassy smell and are excellent in taste and flavor, especially in a rich and milky taste, can be obtained.